DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Size effect characteristics and influences on fatigue behavior of laser powder bed fusion of thin wall GRCop-42 copper alloy

Journal Article · · Heliyon
ORCiD logo [1];  [2]; ORCiD logo [3];  [4]
  1. NASA Marshall Space Flight Center (MSFC), Huntsville, AL (United States); Univ. of Alabama, Huntsville, AL (United States)
  2. Univ. of Alabama, Huntsville, AL (United States)
  3. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
  4. Univ. of Arizona, Tucson, AZ (United States)

Size effects, influencing a material's strength, elongation, fatigue limit, and longevity, depend on the operative and dominant deformation and failure mechanisms. This study explores the size effects in additive manufactured (AM) GRCop-42 (Cu-4at%Cr-2at%Nb) thin wall structures fabricated via laser-powder bed fusion (L-PBF) and their impact on fatigue life. The influence of internal defects and surface topography on the fatigue life of specimens in both as-built and hot isostatic pressed (HIP) conditions across different thicknesses is investigated. Where micro-computed tomography (μCT) was used to quantify the internal porosity of as-built, pristine HIP'd, and fatigued HIP'd specimens, and laser microscopy was employed to quantify the surface topography of specimens prior to fatigue. Additionally, quasi-static tests were used to establish baseline mechanical properties (i.e. yield strength (YS), ultimate tensile strength (UTS), and elongation) to frame fatigue testing conditions. Results indicate a significant enhancement in fatigue life for HIP'd specimens for both thicknesses, with internal defects depicting a greater impact than surface topography. Furthermore, fractographic analysis suggests that thicker specimens exhibit higher resistance to crack propagation during fatigue testing in the absence of substantial porosity. Thus, the size effects observed on the fatigue life of L-PBF GRCop-42 appears to be dominated by internal defects.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
2333845
Journal Information:
Heliyon, Journal Name: Heliyon Journal Issue: 7 Vol. 10; ISSN 2405-8440
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (38)

Understanding slip activity and void initiation in metals using machine learning-based microscopy analysis journal March 2022
Size effect due to contour laser scanning in 316L stainless steel produced by laser powder bed fusion journal November 2021
Quantification and characterisation of porosity in selectively laser melted Al–Si10–Mg using X-ray computed tomography journal January 2016
Strengthening mechanism of friction stir processed and post heat treated NiAl bronze alloy: Effect of rotation rates journal February 2017
Cyclic plasticity at pores and inclusions in cast Al–Si alloys journal July 2003
Improvement of microstructure and property of cold-sprayed Cu–4at.%Cr–2at.%Nb alloy by heat treatment journal August 2006
Fatigue behavior and modeling of additively manufactured IN718: The effect of surface treatments and surface measurement techniques journal April 2022
Fatigue Performance of Laser Additive Manufactured Ti–6Al–4V in Very High Cycle Fatigue Regime up to 109 Cycles journal December 2015
Fracture Characteristics and Heat treatment of Laser Powder Bed Fusion additively manufactured GRCop-84 Copper journal July 2021
Recent advances on size effect in metal fatigue under defects: a review journal March 2021
Copper-based alloys for structural high-heat-flux applications: a review of development, properties, and performance of Cu-rich Cu–Cr–Nb alloys journal October 2020
Microstructure-topology relationship effects on the quasi-static and dynamic behavior of additively manufactured lattice structures journal August 2019
Influence of reversible and non-reversible fatigue on the microstructure and mechanical property evolution of 7075-T6 aluminum alloy journal April 2021
Characterization of bulk to thin wall mechanical response transition in powder bed AM journal August 2016
Directed energy deposition GRCop-42 copper alloy: Characterization and size effects journal October 2022
Investigation into spatter behavior during selective laser melting of AISI 316L stainless steel powder journal December 2015
Size effect in S–N curves: A fractal approach to finite-life fatigue strength journal May 2009
Microstructure and mechanical properties of additive manufactured copper alloy journal September 2016
The Effectiveness of Hot Isostatic Pressing for Closing Porosity in Titanium Parts Manufactured by Selective Electron Beam Melting journal March 2016
Effects of specimen size on fatigue life of metallic materials in high‐cycle and very‐high‐cycle fatigue regimes journal February 2016
Influence of defects on mechanical properties of Ti–6Al–4V components produced by selective laser melting and electron beam melting journal December 2015
Effects of Post-processing on the Surface Finish, Porosity, Residual Stresses, and Fatigue Performance of Additive Manufactured Metals: A Review journal July 2021
Effects of thickness and orientation on the small scale fracture behaviour of additively manufactured Ti-6Al-4V journal September 2018
Damage evolution and failure mechanisms in additively manufactured stainless steel journal January 2016
Fundamental aspects of hot isostatic pressing: An overview journal December 2000
Fatigue behavior and modeling for additive manufactured 304L stainless steel: The effect of surface roughness journal December 2020
Fatigue life distribution and size effect in ductile cast iron for wind turbine components journal January 2011
Fatigue behaviour of additive manufactured materials: An overview of some recent experimental studies on Ti‐6Al‐4V considering various processing and loading direction effects journal February 2019
Estimating the fatigue stress concentration factor of machined surfaces journal September 2002
Multiaxial fatigue behavior of wrought and additive manufactured Ti-6Al-4V including surface finish effect journal July 2017
The Effect of Stress Relief on the Mechanical and Fatigue Properties of Additively Manufactured AlSi10Mg Parts journal November 2019
Porosity Measurements and Analysis for Metal Additive Manufacturing Process Control
  • Slotwinski, John A.; Garboczi, Edward J.; Hebenstreit, Keith M.
  • Journal of Research of the National Institute of Standards and Technology, Vol. 119 https://doi.org/10.6028/jres.119.019
journal January 2014
Defects in additive manufactured metals and their effect on fatigue performance: A state-of-the-art review journal April 2021
Size Effect on the Fatigue Performance of 18CrNiMo7‐6 Alloy Steel journal May 2021
Effects of porosity on the mechanical properties of additively manufactured components: a critical review journal December 2020
Non-destructive testing of metal-based additively manufactured parts and processes: a review journal October 2023
Accumulation and evolution of elastically induced defects under cyclic loading: Quantification and subsequent properties journal October 2019
Size effects on microstructure and mechanical properties of additively manufactured copper–chromium–niobium alloy journal July 2021